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Biomedical subjects

M Frank

Publications and source records attributed to M Frank.

At least 271 records · Page 15Linked to original sources
PubMed1977

A study of prostaglandin F2alpha as the luteolysin in swine: II Characterization and comparison of prostaglandin F, estrogens and progestin concentrations in utero-ovarian vein plasma of nonpregnant and pregnant gilts.

Polyvinyl catheters were inserted into the right and left utero-ovarian veins (UOV) and saphenous vein (SV) and artery (SA) of six non-pregnant (O) and five pregnant (P) gilts on day 11 after onset estrus. Beginning on day 12, UOV blood samples were collected at 15-min intervals from 0800 to 1100 hr and 2000 to 2300 hr, and single samples were taken at 1200 and 2400 hrs. Peripheral blood (SA or SV) was sampled at 0800, 1200, 2000 and 2400 hr until gilts returned to estrus (X = 20.6 days) or day 24 of pregnancy. UOV plasma PGF concentrations (ng/ml; n = 1929) were measured by RIA. Status (P vs O) by day interactions were detected (P less than .01) but variances among treatments were heterogenous (P less than .01). Curvilinear day trends were detected for PGF in 0 gilts (P less than .01) but not P gilts. PGF peaks, defined as concentrations greater than two SD above the mean concentration for each gilt, occurred with greater frequency (chi2 = 16.4; P less than .01) in O than P gilts; and mean peak levels (X +/- SE) were 5.04 +/- .27 and 3.84 +/- .13 ng/ml, respectively. Progesterone concentrations were maintained in pregnant pigs and were indicative of luteal maintenance. Systematic differences in day trends of utero-ovarian venous plasma estradiol were detected between O and P pigs. These differences may be of paramount physiological importance and are discussed.

Animals↗
PubMed1977

A study of prostaglandin F2alpha as the luteolysin in swine: III effects of estradiol valerate on prostaglandin F, progestins, estrone and estradiol concentrations in the utero-ovarian vein of nonpregnant gilts.

Polyvinyl catheters were placed into the right and left utero-ovarian veins and saphenous vein and artery of three control (C) and four estradiol valerate (EV) treated gilts on Day 9 after onset of estrus. The EV treated gilts received 5mg EV/day on Days 11 through 15 after onset of estrus. On Days 12 through 17 utero-ovarian vein blood samples were collected at 15 min intervals from 0700 to 1000 hr and 1900 to 2200 hr and single samples were taken at 1100 and 2300 hr. Peripheral blood samples (saphenous vein or artery) were taken at 0700, 1100, 1900 and 2300 hr from Day 12 until the control gilts returned to estrus or until Day 25 for EV treated gilts and used to measure plasma steroid hormone concentrations. Utero-ovarian vein prostaglandin F (gf) concentrations (ng/ml, n-1,177) were measured by RIA. Status (control vs EV treated gilts) by day interactions were detected (P=.10). Curvilinear day trends were detected for plasma PGF concentrations in control (P less than .01) but not EV treated gilts. PGF concentrations (X +/- S.D.) for control and EV treated gilts were 1.20 +/- 2.08 and .26 +/- .84 ng/ml, respectively. PGF peaks (concentrations greater than X + 2 S.D.) occurred with greater frequency in control gilts (X2 =4.87; P less than .05). The interestrus interval (X +/- S.E.) for control and treated gilts was 19.0 +/- .6 and 146.5 +/- 74.8 days, respectively. Data indicate tht t estradiol valerate may exert its luteotrophic effect by preventing PGF release from the uterus.

Animals↗
PubMed1977

The effects of grayanotoxin I and alpha-dihydrograyanotoxin II on guinea-pig myocardium.

We have demonstrated recently that grayanotoxin I (GTX I) produces a positive inotropic effect in isolated guinea-pig atria. In order to determine whether this effect of GTX I is related to the reported action of this compound to increase the sodium permeability of cytoplasmic membranes, the effect of GTX I and alpha-dihydrograyanotoxin II (alpha-2H-GTX II) on electrical and mechanical properties and transmembrane cation movements were studied in guinea-pig myocardium. In electrically driven guinea-pig left atrial preparations, both grayanotoxins produced a slight depolarization and appear to decrease the upstroke velocity of the action potential, with a concomitant increase in isometric contractile force in the presence or absence of propranolol. Pretreatment with propranolol shifted the dose-response curves for the inotropic effect of both grayanotoxins slightly to the right. The magnitudes of changes in the electrical and mechanical properties induced by GTX I and alpha-2H-GTX II were similar. The rate of development and subsequent washout of the positive inotropic effects, however, was faster with alpha-2H-GTX II than with GTX I, consistent with a previous report that the action of alpha-2H-GTX II to increase membrane sodium permeability develops more rapidly than that of GTX I. At higher concentrations, both grayanotoxins produced arrhythmias. Arrhythmias induced by GTX I were characterized by extrasystoles whereas those induced by alpha-2H-GTX II were characterized by initial extrasystoles followed by a failure of the atria to follow electrical stimulation. Positive inotropic and arrhythmic effects of both grayanotoxins were reversible after the washout of the drug. Both types of arrhythmias produced by either GTX I or alpha-2H-GTX II were reversed by tetrodotoxin, an agent which has been demonstrated to antagonize the action of the grayanotoxins to increase membrane sodium permeability. Although both grayanotoxins had no marked effect on partially purified Na+, K+-adenosine triphosphatase, they produced dose-dependent increases in ouabain-sensitive 86Rb uptake of ventricular slices under conditions in which the intracellular sodium concentration determines the rate of active monovalent cation transport by the Na+, K+-adenosine triphosphatase system. These data suggest that the positive inotropic effects of grayanotoxins are due to an increased membrane sodium permeability and are consistent with a hypothesis that alterations in transmembrane sodium movements result in an altered myocardial contractility.

Action Potentials↗
PubMed1977

[Phenyketonuria associated with Rubinstein-Taybi syndrome, spondylic dysplasia, left vascular shrinking of adrenal gland (author's transl)].

Report of a 10 year old girl, who demonstrated the following diseases independent from each other: Phenylketonuria, Rubinstein-Taybi syndrome, dysplasias of the skeleton, especially dysplasia of the vertebra and finally, left-sided shrinkes adrenal gland, which caused presumably an increased production of androgens with a premature pubarche.

Abnormalities, Multiple↗
PubMed1977

Atmospheric fungi in the desert town of Arad and in the coastal plain of Israel.

A two years' volumetric survey of the airborne fungi in the arid town of Arad revealed markedly lower spore concentrations than in the coastal region of the country. Low incidence prevailed throughout the year except for high peaks in October-November, closely related to the distribution of Cladosporium spores. Air-spora composition, annual frequency and seasonal variation of fungal genera and species at the two sites were compared.

Air Microbiology↗
PubMed1976

Acute acquired toxoplasmosis.

A case of acute acquired toxoplasmosis presenting as a fever of unknown origin is described in a 62-year-old man. The diagnosis was prompted by the presence of Toxoplasma gondii in lymph nodes obtained at abdominal laparotomy. The unusual features of the case include the patient's age, the presence of cysts in the lymph node, and itc clinical presentation as a prolonged remittent fever.

Acute Disease↗
PubMed1976

Effects of grayanotoxin I on cardiac Na + K + -adenosine triphosphatase activity, transmembrane potential and myocardial contractile force.

The relationship between altered transmembrane sodium movements and myocardial contractility was studied by opposing the action of the sodium pump with grayanotoxin I (GTX), an agent previously shown to increase resting sodium influx. GTX failed to affect Na+,K+-adenosine triphosphatase activity in vitro in concentrations as high as 0.1 mM. In electrically driven left atrial preparations of guinea-pig hearts, 1 mugM GTX produced a slight depolarization and appeared to decrease the upstroke velocity of the action potential, GTX (0.1-1 mugM) also produced a positive inotropic effect which developed over a 20-minute period. At higher concentrations, GTX produced arrhythmias. These effects of GTX were also observed in the presence of 10 mugM propranolol. Positive inotropic and arrhythmic effects of GTX were reversible after washout of the drug. These effects of GTX were also reversed by tetrodotoxin, an agent which has been shown to counteract the effect of GTX on sodium permeability. These data are consistent with a hypothesis that altered transmembrane sodium movement effects myocardial contractility.

Adenosine Triphosphatases↗
PubMed1976

Effects of ryanodine on the contractile force of potassium-depolarized hearts.

The relationship between cellular calcium movements and contractility was indirectly assessed in Langendorff-preparations of guinea pig hearts perfused with either Krebs-Henseleit solution or a high-potassium (22 mM) solution containing 2.4 X 10(-8) M isoproterenol. The addition of either D600 (2.4-24.0 X 10(-8) M) or ryanodine (0.24-24.0 X 10(-6) M) to hearts perfused with Krebs-Hanseleit solution produced a concentration-dependent reduction in contractile force. In potassium-depolarized, isoproterenol-restored hearts, the negative inotropic action of D600 exhibited concentration-and time-dependent changes similar to those observed in Krebs-Hanseleit solution. In contrast, addition of 0.24-75.0 X 10(6) M ryanodine to potassium-depolarized, isoproterenol-restored hearts produce a time-dependent reduction in tension followed by a concentration-dependent rebound in contractile force. These results have been interpreted to be a consequence of the respective actions of D600 and ryanodine on Ca2+ influx and on intracellular calcium stores.

Alkaloids↗
PubMed1975

Effect of ryanodine on myocardial calcium.

The effects of ryanodine and ryanodine steady-state condition (RSSC) on contractile-related calcium were examined in isolated guinea pig left atrial muscle. 1. RSSC is a specific irreversible condition occurring after a brief exposure to 1 x 10(-7) M ryanodine, followed by washing. It is characterized by elimination of the contraction following a 10-sec rest interval (post-rest) and prolongation of the associated action potential duration (AP50%) from 78.9 to 160.8 msec with minimal alteration in steady-state tension development determined at 1 Hz. 2. Induction of RSSC with a ryanodine-bovine serum albumin conjugate produced similar alterations in post-rest contractile strength and action potential duration. 3. In the presence of 1 x 10(-7) M ryanodine, guinea pig left atria exhibit a significant increase in total 45Ca efflux from two rapidly exchangeable compartments (compartment 1, t1/2=1.58 min; compartment 2, t1/2=8.20 min). 4. In atria loaded after the induction of RSSC, total 45Ca release was significantly reduced by 7.2% of the total exchange. 5. The 45Ca exchange space for RSSC atria was reduced from 23.22 +/- 0.81 to 19.85 +/- 1.22 ml per 100 g muscle without a significant reduction in the total exchange space. 6. From these results, it is concluded that the effects of low concentrations of ryanodine and RSSC are to alter the contractile calcium levels of the tissue, primarily from sarcolemmal membrane sites which regulate post-rest contractile strength and action potential duration.

Action Potentials↗
PubMed1975

Nucleocytoplasmic transport and distribution of an amino acid, in situ.

Ultra-low temperature techniques (microdissection and autoradiography) were used to study the nucleocytoplasmic distribution and transport of alpha-aminoisobutyric acid (AIB) in an amino acid-accumulating cell. In amphibiam oocytes incubated in AIB, the nuclear concentration of this non-metabolizable amino acid exceeds the cytoplasmic concentration by 45%, remaining constant both over time and variation in substrate concentration. The kinetics of uptake suggest that this nucleo-cytoplasmic asymmetry arises from solubility differences between the 2 compartments, and that the nuclear envelope plays a negligible role in amino acid transport. A solute exclusion model is offered to explain the nucleocytoplasmic asymmetry.

Aminoisobutyric Acids↗
PubMed1975

Membrane receptor sites for the identification of lymphoreticular cells in benign and malignant conditions.

The cells of the lymphoreticular system are heterogeneous both morphologically and functionally. The bone marrow derived (B) lymphocyte can be identified by the presence of easily detectable surface immunoglobulin and a receptor for antigen-antibody-complement (EAC) complexes. Monocytes and histiocytes also bear a receptor for EAC and in addition possess a receptor for cytophilic antibody detected with red cell--IgG complexes (IgGEA). In man, thymus derived (T) lymphocytes form non-immune rosettes with sheep red blood cells (E). We have examined a number of malignant lymphoreticular populations for the presence of the EAC, EA, and E receptors on suspensions of cells and have adapted the technique to demonstrate the EAC and EA receptors on frozen tissue sections. Rosetted malignant cells can also be cytologically examined on Millipore filters. The malignant cells both in section and suspension from the spleens and lymph nodes of 6 patients with nodular lymphoma bound EAC but not IgGEA or E; by these criteria these malignant cells are of B lymphocytic origin. The malignant cells from the spleens of 2 patients with leukaemic reticuloendotheliosis and 1 patient with malignant histiocytosis could be classified as being of histiocytic origin by the selective binding of IgGEA. In 3 cases of diffuse lymphocytic lymphoma the malignant cells bound only E and are therefore of T lymphocytic origin. The application of these techniques to the classification of malignant lymphoma may lead to important theoretical and therapeutic advances.

Animals↗